US: And then there were nine

It was no accident that the day after the Democratic national convention ended last week, both President Barack Obama and Mitt Romney, his Republican challenger, found themselves rallying the party faithful in Iowa and New Hampshire. Just as it is no accident that Mr Romney was in Nevada on Tuesday and Mr Obama will be there on Wednesday.

Polls show the presidential election in November will be exceptionally close, but the race is even tighter than it looks nationally. It hinges on nine swing states, which both candidates will be visiting repeatedly in the next 55 days. “We’ll be back a lot to Ohio,” Mr Romney told voters at a machine tool plant in Mansfield, deep in the Republican heartland, on Tuesday.

Campaigning a day earlier, Mr Obama put the arithmetic simply. “If we win Palm Beach County, we will win Florida,” he said during a two-day bus tour across the state. “And if we win Florida, we win this election.”

This highlights the peculiar calculus of US elections. To win, one of the candidates must garner 270 electoral college votes – the ballots allocated to states according to population. And, as the 2000 contest in which George W. Bush narrowly defeated Al Gore proved, each one counts.

That means both candidates will spend a great deal of time campaigning in Ohio and Florida – with 18 and 29 electoral college votes respectively – between now and November 6. But smaller states such as Iowa and New Hampshire, with six and four votes each, will also see plenty of Mr Obama and Mr Romney.

In addition to those four, the swing states on which the battle will be focused are Colorado, Nevada, North Carolina, Virginia and Wisconsin. Mr Obama won them all in 2008 but they are in the balance this year – none more so than North Carolina, where Mr Romney appears to have the advantage. National polls show the president enjoying a bounce in support following the Democratic convention – held, by no coincidence, in Charlotte, North Carolina, last week – but the race remains tight.

However, the number of battleground states in play seems to have shrunk in recent weeks. Many analysts say Pennsylvania, which Mr Obama won in 2008 but Mr Romney hoped to flip, is a safe state for the president. And Mr Romney’s supporters are all but giving up in his home state of Michigan.

The three most-watched polling averages now show Mr Obama winning every battleground state except North Carolina. Add in Michigan and Pennsylvania, and he would take 332 electoral votes, Mr Romney only 206.

“We’ve said all along that this race will be close across the board, and polls will move up and down,” says Adam Fetcher of the Obama campaign. “Coming out of Charlotte, the small lead we continue to see in battleground states is a huge problem for the Romney campaign.”

But that could be wishful thinking as a second clean sweep of the swing states is unlikely. Mr Romney’s team is running 15 different advertisements across the nine states and has made eight times as many phone calls this year as the campaign of John McCain, the Republican candidate, did in 2008. “We’re going to be everywhere, across all these states,” says Sarah Pompei of the Romney campaign.

In the home state of Paul Ryan, the Republican vice-presidential candidate, a new advert declares: “Here in Wisconsin, we’re not better off under Obama. There’s a prairie fire of debt that grows over $3bn per day.” Democrats have won in Wisconsin in the six presidential elections since 1988.

The Obama campaign is running targeted adverts across the swing states, although there are questions about their impact. Residents of these states, which have been on the receiving end of more than $100m worth of adverts this election season, say that they are starting to tune them out.

In logistical terms, at least, the president enjoys a clear advantage, with field offices and a volunteer base kept alive since 2008. While Mr Romney has 35 field offices in Ohio, for example, Mr Obama has 77.

Ohio is a must-win for Mr Romney: no Republican has won the White House without it. “I’m assuming it will be a tight race all the way through to November,” says Professor Nathaniel Swigger of Ohio State University. The Real Clear Politics average of polls gives Mr Obama an edge of only 2.2 per cent.

The incumbent’s campaign is touting the president’s rescue of the car industry in Michigan and neighbouring Ohio following the financial crisis, which Mr Romney opposed. “Ohio auto­workers are leading the recovery, with autos supporting one out of eight Ohio jobs and workers in 80 counties,” says the narrator in a television commercial for the president’s campaign.

But the Romney campaign is not conceding working-class votes. “In the blue-collar areas of Ohio, in the south-east of the state, coal is a big issue,” Ms Pompei says, adding that the issue is helping generate support for the Republican in Democratic areas.

Iowa looks better for Mr Romney. “We’re a long way from 2008, when Obama won Iowa by nine points,” says Prof Tim Hagle of the University of Iowa, noting that it swung sharply Republican in the 2010 mid-term elections. “It’s all going to boil down to turnout,” he says. “This isn’t just about reaching out to independents, this is about getting the base out.”

In Florida, where the 2000 election was decided, Mr Obama has made many more visits than Mr Romney – and former president Bill Clinton returned on Tuesday to campaign for the incumbent. However, their opponents have gained traction in the area between Tampa Bay and Orlando, home to half of Florida’s registered Republican voters, since holding their convention in Tampa last month.

“Republicans have used the convention to get better organised,” says Prof Susan MacManus of South Florida University, based in Tampa. “They know they have a turnout battle on their hands and the energy is there.”

As the election looms, voters in the swing states will find themselves becoming familiar – perhaps too familiar – with the men duelling for the White House.